arch/x86/kernel/reboot.c

   1 #include <linux/module.h>
   2 #include <linux/reboot.h>
   3 #include <linux/init.h>
   4 #include <linux/pm.h>
   5 #include <linux/efi.h>
   6 #include <acpi/reboot.h>
   7 #include <asm/io.h>
   8 #include <asm/apic.h>
   9 #include <asm/desc.h>
  10 #include <asm/hpet.h>
  11 #include <asm/pgtable.h>
  12 #include <asm/proto.h>
  13 #include <asm/reboot_fixups.h>
  14 #include <asm/reboot.h>
  15 #include <asm/pci_x86.h>
  16 #include <asm/virtext.h>
  17 #include <asm/cpu.h>
  18
  19 #ifdef CONFIG_X86_32
  20 # include <linux/dmi.h>
  21 # include <linux/ctype.h>
  22 # include <linux/mc146818rtc.h>
  23 #else
  24 # include <asm/iommu.h>
  25 #endif
  26
  27 /*
  28  * Power off function, if any
  29  */
  30 void (*pm_power_off)(void);
  31 EXPORT_SYMBOL(pm_power_off);
  32
  33 static const struct desc_ptr no_idt = {};
  34 static int reboot_mode;
  35 enum reboot_type reboot_type = BOOT_KBD;
  36 int reboot_force;
  37
  38 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
  39 static int reboot_cpu = -1;
  40 #endif
  41
  42 /* This is set if we need to go through the 'emergency' path.
  43  * When machine_emergency_restart() is called, we may be on
  44  * an inconsistent state and won't be able to do a clean cleanup
  45  */
  46 static int reboot_emergency;
  47
  48 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
  49 bool port_cf9_safe = false;
  50
  51 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
  52    warm   Don't set the cold reboot flag
  53    cold   Set the cold reboot flag
  54    bios   Reboot by jumping through the BIOS (only for X86_32)
  55    smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
  56    triple Force a triple fault (init)
  57    kbd    Use the keyboard controller. cold reset (default)
  58    acpi   Use the RESET_REG in the FADT
  59    efi    Use efi reset_system runtime service
  60    pci    Use the so-called "PCI reset register", CF9
  61    force  Avoid anything that could hang.
  62  */
  63 static int __init reboot_setup(char *str)
  64 {
  65         for (;;) {
  66                 switch (*str) {
  67                 case 'w':
  68                         reboot_mode = 0x1234;
  69                         break;
  70
  71                 case 'c':
  72                         reboot_mode = 0;
  73                         break;
  74
  75 #ifdef CONFIG_X86_32
  76 #ifdef CONFIG_SMP
  77                 case 's':
  78                         if (isdigit(*(str+1))) {
  79                                 reboot_cpu = (int) (*(str+1) - '0');
  80                                 if (isdigit(*(str+2)))
  81                                         reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
  82                         }
  83                                 /* we will leave sorting out the final value
  84                                    when we are ready to reboot, since we might not
  85                                    have set up boot_cpu_id or smp_num_cpu */
  86                         break;
  87 #endif /* CONFIG_SMP */
  88
  89                 case 'b':
  90 #endif
  91                 case 'a':
  92                 case 'k':
  93                 case 't':
  94                 case 'e':
  95                 case 'p':
  96                         reboot_type = *str;
  97                         break;
  98
  99                 case 'f':
 100                         reboot_force = 1;
 101                         break;
 102                 }
 103
 104                 str = strchr(str, ',');
 105                 if (str)
 106                         str++;
 107                 else
 108                         break;
 109         }
 110         return 1;
 111 }
 112
 113 __setup("reboot=", reboot_setup);
 114
 115
 116 #ifdef CONFIG_X86_32
 117 /*
 118  * Reboot options and system auto-detection code provided by
 119  * Dell Inc. so their systems "just work". :-)
 120  */
 121
 122 /*
 123  * Some machines require the "reboot=b"  commandline option,
 124  * this quirk makes that automatic.
 125  */
 126 static int __init set_bios_reboot(const struct dmi_system_id *d)
 127 {
 128         if (reboot_type != BOOT_BIOS) {
 129                 reboot_type = BOOT_BIOS;
 130                 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
 131         }
 132         return 0;
 133 }
 134
 135 static struct dmi_system_id __initdata reboot_dmi_table[] = {
 136         {       /* Handle problems with rebooting on Dell E520's */
 137                 .callback = set_bios_reboot,
 138                 .ident = "Dell E520",
 139                 .matches = {
 140                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 141                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 142                 },
 143         },
 144         {       /* Handle problems with rebooting on Dell 1300's */
 145                 .callback = set_bios_reboot,
 146                 .ident = "Dell PowerEdge 1300",
 147                 .matches = {
 148                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 149                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 150                 },
 151         },
 152         {       /* Handle problems with rebooting on Dell 300's */
 153                 .callback = set_bios_reboot,
 154                 .ident = "Dell PowerEdge 300",
 155                 .matches = {
 156                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 157                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 158                 },
 159         },
 160         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
 161                 .callback = set_bios_reboot,
 162                 .ident = "Dell OptiPlex 745",
 163                 .matches = {
 164                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 165                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 166                 },
 167         },
 168         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
 169                 .callback = set_bios_reboot,
 170                 .ident = "Dell OptiPlex 745",
 171                 .matches = {
 172                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 173                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 174                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 175                 },
 176         },
 177         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 178                 .callback = set_bios_reboot,
 179                 .ident = "Dell OptiPlex 745",
 180                 .matches = {
 181                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 182                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 183                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 184                 },
 185         },
 186         {   /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 187                 .callback = set_bios_reboot,
 188                 .ident = "Dell OptiPlex 330",
 189                 .matches = {
 190                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 191                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 192                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 193                 },
 194         },
 195         {   /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 196                 .callback = set_bios_reboot,
 197                 .ident = "Dell OptiPlex 360",
 198                 .matches = {
 199                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 200                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 201                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 202                 },
 203         },
 204         {       /* Handle problems with rebooting on Dell 2400's */
 205                 .callback = set_bios_reboot,
 206                 .ident = "Dell PowerEdge 2400",
 207                 .matches = {
 208                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 209                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 210                 },
 211         },
 212         {       /* Handle problems with rebooting on Dell T5400's */
 213                 .callback = set_bios_reboot,
 214                 .ident = "Dell Precision T5400",
 215                 .matches = {
 216                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 217                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 218                 },
 219         },
 220         {       /* Handle problems with rebooting on HP laptops */
 221                 .callback = set_bios_reboot,
 222                 .ident = "HP Compaq Laptop",
 223                 .matches = {
 224                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 225                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 226                 },
 227         },
 228         {       /* Handle problems with rebooting on Dell XPS710 */
 229                 .callback = set_bios_reboot,
 230                 .ident = "Dell XPS710",
 231                 .matches = {
 232                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 233                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 234                 },
 235         },
 236         {       /* Handle problems with rebooting on Dell DXP061 */
 237                 .callback = set_bios_reboot,
 238                 .ident = "Dell DXP061",
 239                 .matches = {
 240                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 241                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 242                 },
 243         },
 244         {       /* Handle problems with rebooting on Sony VGN-Z540N */
 245                 .callback = set_bios_reboot,
 246                 .ident = "Sony VGN-Z540N",
 247                 .matches = {
 248                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 249                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 250                 },
 251         },
 252         { }
 253 };
 254
 255 static int __init reboot_init(void)
 256 {
 257         dmi_check_system(reboot_dmi_table);
 258         return 0;
 259 }
 260 core_initcall(reboot_init);
 261
 262 /* The following code and data reboots the machine by switching to real
 263    mode and jumping to the BIOS reset entry point, as if the CPU has
 264    really been reset.  The previous version asked the keyboard
 265    controller to pulse the CPU reset line, which is more thorough, but
 266    doesn't work with at least one type of 486 motherboard.  It is easy
 267    to stop this code working; hence the copious comments. */
 268 static const unsigned long long
 269 real_mode_gdt_entries [3] =
 270 {
 271         0x0000000000000000ULL,  /* Null descriptor */
 272         0x00009b000000ffffULL,  /* 16-bit real-mode 64k code at 0x00000000 */
 273         0x000093000100ffffULL   /* 16-bit real-mode 64k data at 0x00000100 */
 274 };
 275
 276 static const struct desc_ptr
 277 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
 278 real_mode_idt = { 0x3ff, 0 };
 279
 280 /* This is 16-bit protected mode code to disable paging and the cache,
 281    switch to real mode and jump to the BIOS reset code.
 282
 283    The instruction that switches to real mode by writing to CR0 must be
 284    followed immediately by a far jump instruction, which set CS to a
 285    valid value for real mode, and flushes the prefetch queue to avoid
 286    running instructions that have already been decoded in protected
 287    mode.
 288
 289    Clears all the flags except ET, especially PG (paging), PE
 290    (protected-mode enable) and TS (task switch for coprocessor state
 291    save).  Flushes the TLB after paging has been disabled.  Sets CD and
 292    NW, to disable the cache on a 486, and invalidates the cache.  This
 293    is more like the state of a 486 after reset.  I don't know if
 294    something else should be done for other chips.
 295
 296    More could be done here to set up the registers as if a CPU reset had
 297    occurred; hopefully real BIOSs don't assume much. */
 298 static const unsigned char real_mode_switch [] =
 299 {
 300         0x66, 0x0f, 0x20, 0xc0,                 /*    movl  %cr0,%eax        */
 301         0x66, 0x83, 0xe0, 0x11,                 /*    andl  $0x00000011,%eax */
 302         0x66, 0x0d, 0x00, 0x00, 0x00, 0x60,     /*    orl   $0x60000000,%eax */
 303         0x66, 0x0f, 0x22, 0xc0,                 /*    movl  %eax,%cr0        */
 304         0x66, 0x0f, 0x22, 0xd8,                 /*    movl  %eax,%cr3        */
 305         0x66, 0x0f, 0x20, 0xc3,                 /*    movl  %cr0,%ebx        */
 306         0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60,       /*    andl  $0x60000000,%ebx */
 307         0x74, 0x02,                             /*    jz    f                */
 308         0x0f, 0x09,                             /*    wbinvd                 */
 309         0x24, 0x10,                             /* f: andb  $0x10,al         */
 310         0x66, 0x0f, 0x22, 0xc0                  /*    movl  %eax,%cr0        */
 311 };
 312 static const unsigned char jump_to_bios [] =
 313 {
 314         0xea, 0x00, 0x00, 0xff, 0xff            /*    ljmp  $0xffff,$0x0000  */
 315 };
 316
 317 /*
 318  * Switch to real mode and then execute the code
 319  * specified by the code and length parameters.
 320  * We assume that length will aways be less that 100!
 321  */
 322 void machine_real_restart(const unsigned char *code, int length)
 323 {
 324         local_irq_disable();
 325
 326         /* Write zero to CMOS register number 0x0f, which the BIOS POST
 327            routine will recognize as telling it to do a proper reboot.  (Well
 328            that's what this book in front of me says -- it may only apply to
 329            the Phoenix BIOS though, it's not clear).  At the same time,
 330            disable NMIs by setting the top bit in the CMOS address register,
 331            as we're about to do peculiar things to the CPU.  I'm not sure if
 332            `outb_p' is needed instead of just `outb'.  Use it to be on the
 333            safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 334          */
 335         spin_lock(&rtc_lock);
 336         CMOS_WRITE(0x00, 0x8f);
 337         spin_unlock(&rtc_lock);
 338
 339         /* Remap the kernel at virtual address zero, as well as offset zero
 340            from the kernel segment.  This assumes the kernel segment starts at
 341            virtual address PAGE_OFFSET. */
 342         memcpy(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
 343                 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
 344
 345         /*
 346          * Use `swapper_pg_dir' as our page directory.
 347          */
 348         load_cr3(swapper_pg_dir);
 349
 350         /* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
 351            this on booting to tell it to "Bypass memory test (also warm
 352            boot)".  This seems like a fairly standard thing that gets set by
 353            REBOOT.COM programs, and the previous reset routine did this
 354            too. */
 355         *((unsigned short *)0x472) = reboot_mode;
 356
 357         /* For the switch to real mode, copy some code to low memory.  It has
 358            to be in the first 64k because it is running in 16-bit mode, and it
 359            has to have the same physical and virtual address, because it turns
 360            off paging.  Copy it near the end of the first page, out of the way
 361            of BIOS variables. */
 362         memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
 363                 real_mode_switch, sizeof (real_mode_switch));
 364         memcpy((void *)(0x1000 - 100), code, length);
 365
 366         /* Set up the IDT for real mode. */
 367         load_idt(&real_mode_idt);
 368
 369         /* Set up a GDT from which we can load segment descriptors for real
 370            mode.  The GDT is not used in real mode; it is just needed here to
 371            prepare the descriptors. */
 372         load_gdt(&real_mode_gdt);
 373
 374         /* Load the data segment registers, and thus the descriptors ready for
 375            real mode.  The base address of each segment is 0x100, 16 times the
 376            selector value being loaded here.  This is so that the segment
 377            registers don't have to be reloaded after switching to real mode:
 378            the values are consistent for real mode operation already. */
 379         __asm__ __volatile__ ("movl $0x0010,%%eax\n"
 380                                 "\tmovl %%eax,%%ds\n"
 381                                 "\tmovl %%eax,%%es\n"
 382                                 "\tmovl %%eax,%%fs\n"
 383                                 "\tmovl %%eax,%%gs\n"
 384                                 "\tmovl %%eax,%%ss" : : : "eax");
 385
 386         /* Jump to the 16-bit code that we copied earlier.  It disables paging
 387            and the cache, switches to real mode, and jumps to the BIOS reset
 388            entry point. */
 389         __asm__ __volatile__ ("ljmp $0x0008,%0"
 390                                 :
 391                                 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
 392 }
 393 #ifdef CONFIG_APM_MODULE
 394 EXPORT_SYMBOL(machine_real_restart);
 395 #endif
 396
 397 #endif /* CONFIG_X86_32 */
 398
 399 static inline void kb_wait(void)
 400 {
 401         int i;
 402
 403         for (i = 0; i < 0x10000; i++) {
 404                 if ((inb(0x64) & 0x02) == 0)
 405                         break;
 406                 udelay(2);
 407         }
 408 }
 409
 410 static void vmxoff_nmi(int cpu, struct die_args *args)
 411 {
 412         cpu_emergency_vmxoff();
 413 }
 414
 415 /* Use NMIs as IPIs to tell all CPUs to disable virtualization
 416  */
 417 static void emergency_vmx_disable_all(void)
 418 {
 419         /* Just make sure we won't change CPUs while doing this */
 420         local_irq_disable();
 421
 422         /* We need to disable VMX on all CPUs before rebooting, otherwise
 423          * we risk hanging up the machine, because the CPU ignore INIT
 424          * signals when VMX is enabled.
 425          *
 426          * We can't take any locks and we may be on an inconsistent
 427          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 428          * VMX and halt.
 429          *
 430          * For safety, we will avoid running the nmi_shootdown_cpus()
 431          * stuff unnecessarily, but we don't have a way to check
 432          * if other CPUs have VMX enabled. So we will call it only if the
 433          * CPU we are running on has VMX enabled.
 434          *
 435          * We will miss cases where VMX is not enabled on all CPUs. This
 436          * shouldn't do much harm because KVM always enable VMX on all
 437          * CPUs anyway. But we can miss it on the small window where KVM
 438          * is still enabling VMX.
 439          */
 440         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 441                 /* Disable VMX on this CPU.
 442                  */
 443                 cpu_vmxoff();
 444
 445                 /* Halt and disable VMX on the other CPUs */
 446                 nmi_shootdown_cpus(vmxoff_nmi);
 447
 448         }
 449 }
 450
 451
 452 void __attribute__((weak)) mach_reboot_fixups(void)
 453 {
 454 }
 455
 456 static void native_machine_emergency_restart(void)
 457 {
 458         int i;
 459
 460         if (reboot_emergency)
 461                 emergency_vmx_disable_all();
 462
 463         /* Tell the BIOS if we want cold or warm reboot */
 464         *((unsigned short *)__va(0x472)) = reboot_mode;
 465
 466         for (;;) {
 467                 /* Could also try the reset bit in the Hammer NB */
 468                 switch (reboot_type) {
 469                 case BOOT_KBD:
 470                         mach_reboot_fixups(); /* for board specific fixups */
 471
 472                         for (i = 0; i < 10; i++) {
 473                                 kb_wait();
 474                                 udelay(50);
 475                                 outb(0xfe, 0x64); /* pulse reset low */
 476                                 udelay(50);
 477                         }
 478
 479                 case BOOT_TRIPLE:
 480                         load_idt(&no_idt);
 481                         __asm__ __volatile__("int3");
 482
 483                         reboot_type = BOOT_KBD;
 484                         break;
 485
 486 #ifdef CONFIG_X86_32
 487                 case BOOT_BIOS:
 488                         machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
 489
 490                         reboot_type = BOOT_KBD;
 491                         break;
 492 #endif
 493
 494                 case BOOT_ACPI:
 495                         acpi_reboot();
 496                         reboot_type = BOOT_KBD;
 497                         break;
 498
 499                 case BOOT_EFI:
 500                         if (efi_enabled)
 501                                 efi.reset_system(reboot_mode ?
 502                                                  EFI_RESET_WARM :
 503                                                  EFI_RESET_COLD,
 504                                                  EFI_SUCCESS, 0, NULL);
 505                         reboot_type = BOOT_KBD;
 506                         break;
 507
 508                 case BOOT_CF9:
 509                         port_cf9_safe = true;
 510                         /* fall through */
 511
 512                 case BOOT_CF9_COND:
 513                         if (port_cf9_safe) {
 514                                 u8 cf9 = inb(0xcf9) & ~6;
 515                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 516                                 udelay(50);
 517                                 outb(cf9|6, 0xcf9); /* Actually do the reset */
 518                                 udelay(50);
 519                         }
 520                         reboot_type = BOOT_KBD;
 521                         break;
 522                 }
 523         }
 524 }
 525
 526 void native_machine_shutdown(void)
 527 {
 528         /* Stop the cpus and apics */
 529 #ifdef CONFIG_SMP
 530
 531         /* The boot cpu is always logical cpu 0 */
 532         int reboot_cpu_id = 0;
 533
 534 #ifdef CONFIG_X86_32
 535         /* See if there has been given a command line override */
 536         if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
 537                 cpu_online(reboot_cpu))
 538                 reboot_cpu_id = reboot_cpu;
 539 #endif
 540
 541         /* Make certain the cpu I'm about to reboot on is online */
 542         if (!cpu_online(reboot_cpu_id))
 543                 reboot_cpu_id = smp_processor_id();
 544
 545         /* Make certain I only run on the appropriate processor */
 546         set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
 547
 548         /* O.K Now that I'm on the appropriate processor,
 549          * stop all of the others.
 550          */
 551         smp_send_stop();
 552 #endif
 553
 554         lapic_shutdown();
 555
 556 #ifdef CONFIG_X86_IO_APIC
 557         disable_IO_APIC();
 558 #endif
 559
 560 #ifdef CONFIG_HPET_TIMER
 561         hpet_disable();
 562 #endif
 563
 564 #ifdef CONFIG_X86_64
 565         pci_iommu_shutdown();
 566 #endif
 567 }
 568
 569 static void __machine_emergency_restart(int emergency)
 570 {
 571         reboot_emergency = emergency;
 572         machine_ops.emergency_restart();
 573 }
 574
 575 static void native_machine_restart(char *__unused)
 576 {
 577         printk("machine restart\n");
 578
 579         if (!reboot_force)
 580                 machine_shutdown();
 581         __machine_emergency_restart(0);
 582 }
 583
 584 static void native_machine_halt(void)
 585 {
 586         /* stop other cpus and apics */
 587         machine_shutdown();
 588
 589         /* stop this cpu */
 590         stop_this_cpu(NULL);
 591 }
 592
 593 static void native_machine_power_off(void)
 594 {
 595         if (pm_power_off) {
 596                 if (!reboot_force)
 597                         machine_shutdown();
 598                 pm_power_off();
 599         }
 600 }
 601
 602 struct machine_ops machine_ops = {
 603         .power_off = native_machine_power_off,
 604         .shutdown = native_machine_shutdown,
 605         .emergency_restart = native_machine_emergency_restart,
 606         .restart = native_machine_restart,
 607         .halt = native_machine_halt,
 608 #ifdef CONFIG_KEXEC
 609         .crash_shutdown = native_machine_crash_shutdown,
 610 #endif
 611 };
 612
 613 void machine_power_off(void)
 614 {
 615         machine_ops.power_off();
 616 }
 617
 618 void machine_shutdown(void)
 619 {
 620         machine_ops.shutdown();
 621 }
 622
 623 void machine_emergency_restart(void)
 624 {
 625         __machine_emergency_restart(1);
 626 }
 627
 628 void machine_restart(char *cmd)
 629 {
 630         machine_ops.restart(cmd);
 631 }
 632
 633 void machine_halt(void)
 634 {
 635         machine_ops.halt();
 636 }
 637
 638 #ifdef CONFIG_KEXEC
 639 void machine_crash_shutdown(struct pt_regs *regs)
 640 {
 641         machine_ops.crash_shutdown(regs);
 642 }
 643 #endif
 644
 645
 646 #if defined(CONFIG_SMP)
 647
 648 /* This keeps a track of which one is crashing cpu. */
 649 static int crashing_cpu;
 650 static nmi_shootdown_cb shootdown_callback;
 651
 652 static atomic_t waiting_for_crash_ipi;
 653
 654 static int crash_nmi_callback(struct notifier_block *self,
 655                         unsigned long val, void *data)
 656 {
 657         int cpu;
 658
 659         if (val != DIE_NMI_IPI)
 660                 return NOTIFY_OK;
 661
 662         cpu = raw_smp_processor_id();
 663
 664         /* Don't do anything if this handler is invoked on crashing cpu.
 665          * Otherwise, system will completely hang. Crashing cpu can get
 666          * an NMI if system was initially booted with nmi_watchdog parameter.
 667          */
 668         if (cpu == crashing_cpu)
 669                 return NOTIFY_STOP;
 670         local_irq_disable();
 671
 672         shootdown_callback(cpu, (struct die_args *)data);
 673
 674         atomic_dec(&waiting_for_crash_ipi);
 675         /* Assume hlt works */
 676         halt();
 677         for (;;)
 678                 cpu_relax();
 679
 680         return 1;
 681 }
 682
 683 static void smp_send_nmi_allbutself(void)
 684 {
 685         apic->send_IPI_allbutself(NMI_VECTOR);
 686 }
 687
 688 static struct notifier_block crash_nmi_nb = {
 689         .notifier_call = crash_nmi_callback,
 690 };
 691
 692 /* Halt all other CPUs, calling the specified function on each of them
 693  *
 694  * This function can be used to halt all other CPUs on crash
 695  * or emergency reboot time. The function passed as parameter
 696  * will be called inside a NMI handler on all CPUs.
 697  */
 698 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 699 {
 700         unsigned long msecs;
 701         local_irq_disable();
 702
 703         /* Make a note of crashing cpu. Will be used in NMI callback.*/
 704         crashing_cpu = safe_smp_processor_id();
 705
 706         shootdown_callback = callback;
 707
 708         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 709         /* Would it be better to replace the trap vector here? */
 710         if (register_die_notifier(&crash_nmi_nb))
 711                 return;         /* return what? */
 712         /* Ensure the new callback function is set before sending
 713          * out the NMI
 714          */
 715         wmb();
 716
 717         smp_send_nmi_allbutself();
 718
 719         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 720         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 721                 mdelay(1);
 722                 msecs--;
 723         }
 724
 725         /* Leave the nmi callback set */
 726 }
 727 #else /* !CONFIG_SMP */
 728 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 729 {
 730         /* No other CPUs to shoot down */
 731 }
 732 #endif